Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 87: Focus Session: Molecular Nanostructures on Surfaces: On-Surface Synthesis and Single-Molecule Manipulation III
O 87.9: Talk
Thursday, March 21, 2024, 17:15–17:30, HE 101
On-Surface Synthesis of Oxygen Annulated Porphyrins — •Joel Deyerling1, Beatrice B. Berna2, Dmytro Biloborodov2, Felix Haag1, Sena Tömekce1, Marc G. Cuxart1, Davide Bonifazi2, and Willi Auwärter1 — 1Physics Department E20, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany — 2Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
Recently the on-surface synthesis of fused porphyrins through C-H activation followed by C-C bond formation has generated considerable interest [1-3]. These porphyrins afford various edges and topologies, thus, offering precise control of their functional properties. From a chemistry point of view, the toolbox is currently limited to C-C coupling, while on-surface C-heteroatom fusing to porphyrins is elusive.
In this context we explore the on-surface oxygen annulation of Ni(II)-tetra- and octahydroxyporphyrins on Au(111). Upon thermal activation, the ortho-positions of the meso-aryl substituents (dihydroxyphenyls) are connected by an O-bridge to the β-pyrrolic positions of the porphyrin macrocycle, creating pyran rings. Employing STM, nc-AFM and high-resolution XPS, we provide a comprehensive characterization of the on-surface reaction. Beyond that, we elucidate how the oxygen tailors the electronic structure and drives the assembly of the achiral molecules into chiral lattices.
[1] Sun, Q. et al., JACS, 142, 18109-18117 (2020).
[2] Yang, X.-Q. et al., ACS Nano, 16, 13092-13100 (2022).
[3] Deyerling, J. et al., J. Phys. Chem. C, 126, 8467-8476 (2022).
Keywords: scanning tunneling microscopy; on-surface synthesis; porphyrin; nc-AFM